Hello ... I don't know if this is the right place for the question, but here goes ... I'm using ArcMap 10.5.1 for a project I'm doing on behalf of a non-profit housing development organization, and I've been attempting to join a Census table to a TIGER shapefile, without luck. In this particular case, I'm attempting to join a table of data at the Census Block level to the appropriate corresponding TIGER shapefile, but I have repeatedly found that the "geoid" numbers fail to match owing to their length (15 numerical digits) and the related tendency of both the shapefile and csv data tables to convert the numbers into exponential versions. This problem only occurs at the Census Block level, perhaps because the Census Block Group geoid number is only 12 digits, versus 15 (without decimals) for Blocks. I've spent hours trying to bypass the obstacle, or to resolve it, with no luck.